Odds Ratio Calculator
Calculate the odds ratio from a 2x2 contingency table to measure the strength of association between an exposure and an outcome. Includes 95% confidence interval.
The odds ratio compares the odds of an outcome between two groups.
2x2 Table:
| Outcome+ | Outcome- | |
|---|---|---|
| Exposed | a | b |
| Unexposed | c | d |
Formula: OR = (a × d) / (b × c)
Interpretation:
- OR = 1: No association
- OR > 1: Exposure increases odds of outcome
- OR < 1: Exposure decreases odds of outcome
95% CI: If the CI includes 1, the association is not statistically significant.